From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hqemgate14.nvidia.com (hqemgate14.nvidia.com [216.228.121.143]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 6ADAF212AAB82 for ; Wed, 3 Jul 2019 10:22:28 -0700 (PDT) Subject: Re: [PATCH 18/22] mm: return valid info from hmm_range_unregister References: <20190701062020.19239-1-hch@lst.de> <20190701062020.19239-19-hch@lst.de> From: Ralph Campbell Message-ID: <0cc37cca-4f3a-40bb-0059-bf3880c171b8@nvidia.com> Date: Wed, 3 Jul 2019 10:22:23 -0700 MIME-Version: 1.0 In-Reply-To: <20190701062020.19239-19-hch@lst.de> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Christoph Hellwig , Dan Williams , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Ben Skeggs Cc: linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, nouveau@lists.freedesktop.org List-ID: On 6/30/19 11:20 PM, Christoph Hellwig wrote: > Checking range->valid is trivial and has no meaningful cost, but > nicely simplifies the fastpath in typical callers. Also remove the > hmm_vma_range_done function, which now is a trivial wrapper around > hmm_range_unregister. > > Signed-off-by: Christoph Hellwig Reviewed-by: Ralph Campbell > --- > drivers/gpu/drm/nouveau/nouveau_svm.c | 2 +- > include/linux/hmm.h | 11 +---------- > mm/hmm.c | 6 +++++- > 3 files changed, 7 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c > index 8c92374afcf2..9d40114d7949 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_svm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c > @@ -652,7 +652,7 @@ nouveau_svm_fault(struct nvif_notify *notify) > ret = hmm_vma_fault(&svmm->mirror, &range, true); > if (ret == 0) { > mutex_lock(&svmm->mutex); > - if (!hmm_vma_range_done(&range)) { > + if (!hmm_range_unregister(&range)) { > mutex_unlock(&svmm->mutex); > goto again; > } > diff --git a/include/linux/hmm.h b/include/linux/hmm.h > index 0fa8ea34ccef..4b185d286c3b 100644 > --- a/include/linux/hmm.h > +++ b/include/linux/hmm.h > @@ -465,7 +465,7 @@ int hmm_range_register(struct hmm_range *range, > unsigned long start, > unsigned long end, > unsigned page_shift); > -void hmm_range_unregister(struct hmm_range *range); > +bool hmm_range_unregister(struct hmm_range *range); > long hmm_range_snapshot(struct hmm_range *range); > long hmm_range_fault(struct hmm_range *range, bool block); > long hmm_range_dma_map(struct hmm_range *range, > @@ -487,15 +487,6 @@ long hmm_range_dma_unmap(struct hmm_range *range, > */ > #define HMM_RANGE_DEFAULT_TIMEOUT 1000 > > -/* This is a temporary helper to avoid merge conflict between trees. */ > -static inline bool hmm_vma_range_done(struct hmm_range *range) > -{ > - bool ret = hmm_range_valid(range); > - > - hmm_range_unregister(range); > - return ret; > -} > - > /* This is a temporary helper to avoid merge conflict between trees. */ > static inline int hmm_vma_fault(struct hmm_mirror *mirror, > struct hmm_range *range, bool block) > diff --git a/mm/hmm.c b/mm/hmm.c > index de35289df20d..c85ed7d4e2ce 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -920,11 +920,14 @@ EXPORT_SYMBOL(hmm_range_register); > * > * Range struct is used to track updates to the CPU page table after a call to > * hmm_range_register(). See include/linux/hmm.h for how to use it. > + * > + * Returns if the range was still valid at the time of unregistering. Since this is an exported function, we should have kernel-doc comments. That is probably a separate patch but at least this line could be: Return: True if the range was still valid at the time of unregistering. > */ > -void hmm_range_unregister(struct hmm_range *range) > +bool hmm_range_unregister(struct hmm_range *range) > { > struct hmm *hmm = range->hmm; > unsigned long flags; > + bool ret = range->valid; > > spin_lock_irqsave(&hmm->ranges_lock, flags); > list_del_init(&range->list); > @@ -941,6 +944,7 @@ void hmm_range_unregister(struct hmm_range *range) > */ > range->valid = false; > memset(&range->hmm, POISON_INUSE, sizeof(range->hmm)); > + return ret; > } > EXPORT_SYMBOL(hmm_range_unregister); > > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm